IR公司的IR3477 SupIRBuck是容易使用的高效全集成DC/DC电压稳压器，可提供精确控制的15A输出电压，输入电压从3V到27V，输出电压从0.5V到12V，不需要补偿回路，在非常低输出电流时有极好的效率，可编程开关频率和蔼软起动，主要用在笔记电脑和台式计算机，消费类电子如STB，LCD，TV和打印机等，12V和24V分布电源，通用POL DC/DC转换器以及游戏机和图像卡等.本文介绍了IR3477主要特性，方框图，典型应用电路，演示板电路图和材料清单，以及IRDC3477评估板主要特性，电路图和材料清单.

 The IR3477 SupIRBuckTM is an easy‐to‐use， fully integrated and highly efficient DC/DC voltage regulator. The onboard constant on time hysteretic controller and MOSFETs make
IR3477 a space‐efficient solution that delivers up to 15A of precisely controlled output voltage.

 Programmable switching frequency， soft start， and thermally compensated over current protection allows for a very flexible solution suitable for many different applications and an ideal choice for battery powered applications.

 Additional features include pre‐bias startup， very precise 0.5V reference， under/over voltage shutdown， thermal protection， power good output， and enable input with voltage monitoring capability.

 IR3477主要特性:

Input Voltage Range: 3V to 27V

Output Voltage Range: 0.5V to 12V

Continuous 15A Load Capability

Constant On‐Time Control

Compensation Loop not Required

Excellent Efficiency at Very Low Output Currents

Programmable Switching Frequency and Soft Start

Thermally Compensated Over Current Protection

Power Good Output

Precision Voltage Reference (0.5V， +/‐1%)

Enable Input with Voltage Monitoring Capability

Pre‐bias Start Up

Thermal Shut Down

Under/Over Voltage Fault Protection

Forced Continuous Conduction Mode Option

Small， Low Profile 5mm x 6mm QFN Package

IR3477应用:

Notebook and Desktop Computers

Consumer Electronics – STB， LCD， TV， Printers

12V and 24V Distributed Power Systems

General Purpose POL DC‐DC Converters

Game Consoles and Graphics Cards

图1.IR3477功能方块图

图2.IR3477典型应用电路图

图3.IR3477演示板电路图: VOUT = 1.05V， FS = 300kHz

演示板材料清单(BOM)

IRDC3477评估板主要特性:

VIN = +12V

VCC = +5V

VOUT = +1.05V

IOUT = 0 to 15A

FS = 300kHz @ CCM

L = 1μH

CIN = 22μF (ceramic 1210) + 68μF (electrolytic)

COUT = 47μF (ceramic 0805) + 330μF (PC-CON)

图4.IRDC3477评估板外形和连接图

图5.IRDC3477评估板电路图

IRDC3477评估板材料清单(BOM)